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PubMedDate not supplied

Comparison of an extraaortic counterpulsation device versus intraaortic balloon pumping in severe cardiac failure.

A valveless, single orifice polyurethane ventricle was implanted on the brachiocephalic artery in sheep (n = 14) to provide extraaortic counterpulsation. In parallel, an intraaortic balloon was placed in the descending thoracic aorta. Both devices were pneumatically driven by a standard intraaortic balloon pump (IABP) console at a preload of 40 cc. Severe cardiac failure was induced with high dosages of esmolol. Measured parameters were aortic pressure (PA) and flow (QA), coronary flow (QC), and left ventricular pressure (PLV). Tension time index (TTI), total QA and QC, and end-diastolic aortic pressure (EDP) were computed to compare the efficacy of counterpulsation between assisted and unassisted conditions. Three conditions of inflation/deflation timing were examined: Normal timing (NT), early inflation (EI), and late deflation (LD). Results indicated that extraaortic counterpulsation device actuation yielded statistically significant increases in QC, and significant decreases in EDP and TTI for all timing conditions examined, when compared with unassisted conditions. Flow was significantly increased only for EI and NT timing conditions. Counterpulsation delivered with IABP yielded statistically significant increases in EDP for LD timing, and significant decreases in TTI for NT only. These results indicate that EACD is much less dependent on inflation/deflation timing when compared with IABP. The extraaortic counterpulsation device consistently increases QC and decreases TTI, which enhances the oxygen supply/consumption ratio (S/C) of the left ventricle. The intraaortic balloon pump does not significantly increase S/C in severe cardiac failure, and will increase afterload if deflation timing is not properly set.

Animals↗

PubMedDate not supplied

Pulmonary artery counterpulsation with a skeletal muscle power source.

We evaluated the feasibility of using skeletal muscle (SM) to provide pulmonary artery (PA) counterpulsation in an acute pulmonary hypertension (PHT) model. PA counterpulsation was achieved in six dogs with a dual chambered pump powered by the latissimus dorsi muscle. A rate-responsive stimulator was used to make the muscle contract in counterpulsation. Graded PHT was induced by infusing 150 microns glass beads into the PA, while RV and PA pressures were monitored. With PA pressures ranging from 19/10 to 115/62 mmHg, effective counterpulsation was observed. The degree of counterpulsation was influenced by the extent of PHT induced, with the amount of RV tension-time index (TTI) unloading correlated with the level of PA systole (r = 0.92). Therefore, results were divided into two groups (Group 1: PA systole less than or equal to 40 mmHg, and Group 2: PA systole greater than 40 mmHg). In Group 1, RV TTI decreased from 11.29 +/- 0.76 to 9.99 +/- 0.72 mmHg.sec, PA diastole increased from 20 +/- 2.3 to 31 +/- 3.0 mmHg, and PA mean increased from 24 +/- 2.2 to 2.9 +/- 2.2 mmHg (all p less than 0.05). In Group 2, RV TT1 decreased from 15.12 +/- 1.83 to 10.99 +/- 0.90 mmHg.sec, PA diastole increased from 41 +/- 3.5 to 64 +/- 6.2 mmHg, and PA mean increased from 49 +/- 4.8 to 55 +/- 5.7 mmHg (all p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Pulmonary artery balloon counterpulsation for right ventricular failure after right ventriculotomy in the swine.

To assess the efficacy of intrapulmonary balloon counterpulsation in the management of right ventricular failure after right ventriculotomy, we undertook an experimental study in a swine model. To mimic the clinical settings more closely, (1) we left the automatic control of the heart intact (2) did not use cardiopulmonary bypass to support the left side of the heart, and (3) induced right ventricular failure by means of a generous surgical incision (50% to 70% of the anterior wall) of the right ventricle. The criteria set for right ventricular failure were (1) 50% increase in right ventricular end-diastolic pressure, (2) 30% decrease in mean arterial pressure, and (3) 30% decrease in cardiac output. Right ventricular failure was attained in all animals studied: A 230% increase in right ventricular end-diastolic pressure, a 43% decrease in cardiac output, and a 34% decrease in mean arterial pressure were evident after the right ventriculotomy. A specially designed intrapulmonary balloon catheter (Datascope Corp., Oakland, N.J.) was placed into the left pulmonary artery through the right ventricular outflow tract. A Datascope console was used for counterpulsation. Effects of counterpulsation for 40 minutes in a 1:1 mode were assessed after surgical induction of right ventricular failure in 14 swine. Each animal served as its own control. The mean hemodynamic changes are outlined: Right ventricular end-diastolic pressure decreased by 48.9% (p = 0.01). Mean arterial pressure increased by 68.8% (p = 0.01) and cardiac output by 44.2% (p = 0.01). Histologic studies disclosed no morphologic damage to the pulmonary artery or valve in the specimens analyzed. In addition, these results were compared with those in a second group of seven swine in which right ventricular failure was induced by right ventriculotomy and a balloon was placed into the left pulmonary artery but not activated. These results of short-term counterpulsation should be evaluated in a longer term model so as to mimic more closely the clinical setting. If the hemodynamic benefits are duplicated, intrapulmonary balloon counterpulsation should be considered as a simple, effective device when right ventricular failure develops after right ventriculotomy. It effectively improves right ventricular function without damaging the pulmonary artery or valve.

Animals↗

PubMed1976

Effect of hypertonic mannitol and intraaortic counterpulsation on regional myocardial blood flow and ventricular performance in dogs during myocardial ischemia.

Studies were performed to determine if intervention with hypertonic mannitol and intraaortic balloon counterpulsation increases regional myocardial blood flow during acute myocardial ischemia. Anesthetized dogs on right heart bypass were studied. Heart rate was kept constant by atrial pacing. Myocardial ischemia was provided by ligating the proximal left anterior descending coronary artery for 12 minute periods. Infusion of hypertonic mannitol begun immediately after ligation increased coronary blood flow to the ischemic area by 36 +/- 9.0% (standard error) (P less than 0.01) and to the nonischemic left ventricle by 21 +/- 8.8% (P less than 0.05) as compared with flow in the same regions during the control coronary ligation. Intraaortic balloon counterpulsation begun immediately after ligation increased regional coronary flow to the ischemic region by 20 +/- 8.4% (P less than 0.05) but did not significantly alter flow to the nonischemic left ventricle as compared with levels during the control ligation. Combined intraaortic counterpulsation and hypertonic mannitol increased coronary flow to the ischemic region by 46 +/- 13% (P less than 0.02) and to the nonischemic left ventricle by 59 +/- 22% (P less than 0.05) as compared with flow during occlusion of the left anterior descending artery with mannitol alone. The data demonstrate that both hypertonic mannitol and intraaortic counterpulsation increase left ventricular ischemic regional flow and that combined hypertonic mannitol and intraaortic balloon counterpulsation provide a greater increase in regional coronary blood flow to both the ischemic and nonischemic regions of the left ventricle than mannitol alone.

Acute Disease↗

PubMed1984

Intraaortic balloon counterpulsation.

The physiologic principle of hemodynamic circulatory support for the failing left ventricle must be directed toward reducing left ventricular work and myocardial oxygen demand and increasing myocardial oxygen supply. This support can best be accomplished with the use of intraaortic balloon counterpulsation. Support of the failing heart after cardiopulmonary bypass was the most frequent indication for counterpulsation treatment in our reported series. This type of assist was required in 5.2 percent of my patients. I reviewed the reports from three medical centers and added our own results in patients who required intraaortic balloon counterpulsation for weaning from cardiopulmonary bypass. Of a total of 399 patients, 255 or 73 percent were weaned off the balloon assist device and of this group, 239 or 60 percent were subsequently discharged from the hospital. Among patients who required intraaortic balloon counterpulsation for postoperative pump failure, 43 (70 percent) of 66 patients were weaned off the intraaortic balloon device, and 35 (53 percent) were later discharged from the hospital. A 24 percent survival rate occurred in patients with cardiogenic shock treated solely with counterpulsation; however, the survival rate increased to 52 percent when those patients subsequently received cardiac catheterization and appropriate surgical intervention.

Assisted Circulation↗

PubMed1997

Intraaortic balloon counterpulsation improves right ventricular failure resulting from pressure overload.

BACKGROUND: Right ventricular (RV) dysfunction is common after heart transplantation, and myocardial ischemia is considered to be a significant contributor. We studied whether intraaortic balloon counterpulsation would improve cardiac function using a model of acute RV pressure overload. METHODS: In 10 anesthetized sheep, RV failure was induced using a pulmonary artery constrictor. Baseline measurements included mean systemic blood pressure, RV peak systolic pressure, cardiac index, and RV ejection fraction. Myocardial and organ perfusion were measured using radioactive microspheres. RESULTS: After pulmonary artery constriction, there was an increase in RV peak systolic pressure (32 +/- 2 to 60 +/- 3 mm Hg; p < 0.01) and a decrease in mean systemic blood pressure (68 +/- 4 to 49 +/- 2 mm Hg; p < 0.01), RV ejection fraction (0.51 +/- 0.04 to 0.16 +/- 0.02; p < 0.01), and cardiac index (2.48 +/- 0.04 to 1.02 +/- 0.11; p < 0.01). Blood flow to the RV did not change significantly, but there was a significant reduction in blood flow to the left ventricle. The initiation of intraaortic balloon counterpulsation (1:1) using a 40-mL intraaortic balloon inserted through the left femoral artery resulted in an increase in mean systemic blood pressure (49 +/- 2 to 61 +/- 3 mm Hg; p < 0.01), cardiac index (1.02 +/- 0.11 to 1.45 +/- 0.14; p < 0.05), RV ejection fraction (0.16 +/- 0.02 to 0.23 +/- 0.02; p < 0.01), and blood flow to the left ventricle. CONCLUSIONS: In a model of right heart failure, the institution of intraaortic balloon counterpulsation caused a significant improvement in cardiac function. Although RV ischemia was not demonstrated, the augmentation of left coronary artery blood flow by intraaortic balloon counterpulsation and subsequent improvement in left ventricular function suggest that left ventricular ischemia contributes to RV dysfunction, presumably through a ventricular interdependence mechanism. Therefore, study of the safety and efficacy of intraaortic balloon counterpulsation in the management of patients with acute right heart dysfunction is warranted.

Animals↗

PubMed2002

Intra-aortic balloon counterpulsation in the emergency department: a 7-year review and analysis of predictors of survival.

BACKGROUND: Intra-aortic balloon pump (IABP) counterpulsation in cardiogenic shock (CS) is suggested as bridging therapy to definite emergency revascularization, heart transplantation and acute valvular repair. Data concerning the use of IABP counterpulsation in an emergency department (ED) are rare. PATIENTS AND METHODS: We reviewed retrospectively the charts of patients who had been treated by IABP counterpulsation in the ED of a tertiary care university hospital during a 7-year period. We analyzed indications for IABP treatment, complications of IABP use and studied various predictors for 30-day survival. RESULTS: Overall 88 (68 male) patients, median age 60 years (IQR 53-69 years) were treated with IABP counterpulsation. CS was caused by acute coronary syndrome (ACS), acute cardiomyopathy decompensation of (CMP) and aortic stenosis (AS) in 77 (87%), ten (12%) and one (1%) patients, respectively. Complications attributed to the insertion or maintenance of IABP were observed in nine (10%) patients. Thirty four patients (38%; 24 male) survived. Compared to non-survivors, these patients were younger (56 vs. 63 years; P<0.023) and had significant lower serum lactate levels before IABP insertion (3 vs. 5.5 mmol/l; P<0.002). Logistic regression analysis identified age (P<0.04) and serum lactate serum level before IABP (P<0.01) as independent predictors for survival. In the 77 patients with ACS PTCA tended to be associated with a higher rate of survival (P<0.09). CONCLUSION: Initiation of IABP counterpulsation in patients with CS in an ED appears safe. Low levels of serum lactate and younger age were independent predictors of survival. In patients with ACS PTCA may contribute to improved outcome.

Acidosis, Lactic↗

PubMed1984

Effects of intraaortic balloon counterpulsation on myocardial blood flow in patients with severe coronary artery disease.

The purpose of this study was to test the hypothesis that myocardial blood flow distal to a critical stenosis would increase during intraaortic balloon counterpulsation. Accordingly, 13 patients with severe coronary artery disease were studied at the time of elective preoperative insertion of an intraaortic balloon catheter. Hemodynamic measurements and measurements of myocardial blood flow were made before and during counterpulsation. Myocardial blood flow was measured with a xenon-133 washout technique. Compared with control measurements, the heart rate decreased from 87.8 +/- 18.8 to 82.8 +/- 13.4 beats/min (p = 0.02) and systolic arterial pressure decreased from 112.1 +/- 17.9 to 97.8 +/- 14.8 mm Hg (p = 0.004) during counterpulsation. Diastolic arterial pressure increased from 72.2 +/- 10.1 to 120.2 +/- 21.4 mm Hg (p = 0.00002) during counterpulsation. Myocardial blood flow for the entire group decreased from 48.8 +/- 14.1 to 42.6 +/- 11.0 ml/100 g per min (p = 0.008). Regional flows in the left anterior descending and circumflex distributions also decreased. Left anterior descending artery blood flow decreased insignificantly from 51.5 +/- 14.4 to 47.4 +/- 11.7 ml/100 g per min (p = not significant), while circumflex flow decreased from 50.7 +/- 12.2 to 41.1 +/- 8.9 ml/100 g per min (p = 0.008). When normalized for the rate-pressure product, myocardial blood flow was 53 +/- 16 X 10(-4) at rest and 55 +/- 12 X 10(-4) (p = not significant) during counterpulsation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1975

Intra-aortic balloon counterpulsation: potential for therapy in hemorrhagic shock with associated myocardial failure.

After attaching appropriate monitoring devices enabling the measurement of the slope of the left ventricular function curve, left atrial pressure, mean aortic pressure, peak left ventricular pressure, and tension time index, three groups of ten dogs were subjected to varying periods of hemorrhagic shock until a slope of their ventricular function curve was reduced to either 75% (Group I), 50% (Group II), or 25% (Group III) of their baseline value. Resuscitation was attempted in all dogs by the intravenous infusion of shed blood plus additional balanced salt solution. This infusate was administered to maintain either the mean aortic pressure within 15 mm Hg of the baseline value or a left atrial pressure of 15 mm Hg, whichever occurred forst. One half of the dogs received, in addition, intra-aortic balloon counterpulsation. All dogs not receiving counterpulsation expired within two hours. There was no apparent effect of counterpulsation on Group I animals. Three of five animals (Group II) and four of five animals (Group III) receiving counterpulsation survived to the end of the experiment with significant (p smaller than .01) improvement in the parameters monitored. The utilization of counterpulsation as an adjunct to treatment in hemorrhagic shock is suggested.

Animals↗

PubMed1979

Arterial counterpulsation in severe refractory heart failure complicating acute myocardial infarction.

The role of arterial counterpulsation was sought in 100 patients with severe refractory cardiac failure complicating myocardial infarction. Seventy-four were in shock and 26 were not. Average duration of counterpulsation was 7.0 days. Hospital survival was 34 per cent (25/74) in shock (predicted less than 10%) and 65 per cent in patients who were not in shock (predicted less than 50%). Survival at 4 years was 10 +/- 4 per cent in shock and 37 +/- 11 per cent in patients not in shock; functional status was class 1 or 2 in 5 of 9 patients in shock and in 8 of 12 survivors not in shock. Results were best when counterpulsation was started early after onset of symptoms, when ischaemic pain was still present, or when a mechanical defect was corrected surgically. Early coronary artery bypass surgery performed alone in 9 patients did not influence survival or functional status. Complications of counterpulsation occurred in 17 patients in shock and in 2 patients not in shock, all but 6 on the first day; none directly caused death. Counterpulsation is an effective and safe adjunct to medical treatment of complicated infarction provided the intervention is prompt.

Adult↗

PubMed1980

Intraaortic balloon counterpulsation with and without reperfusion for myocardial infarction shock.

Forty patients were treated for cardiogenic shock secondary to acute myocardial infarction. Twenty-one (group 1) were treated with intraaortic balloon counterpulsation and 19 (group 2) were treated with counterpulsation and coronary artery bypass grafting. The groups were similar in age, incidence of previous infarction, initial hemodynamics and coronary anatomy. The in-hospital mortality between group 1 (52.4%) and group 2 (42.1%) was not significantly different. The difference in long-term mortality between group 1 and group 2 was substantially different (71.4% vs 47.3%). The subset of group 2 (n = 12) that underwent reperfusion and counterpulsation within 16 hours from the onset of symptoms of infarction had a lower mortality (25.0%) than the subset (n = 7) that underwent operation more than 18 hours after the onset of symptoms (71.4%). The long-term mortality in the subset of group 2 patients operated on within 16 hours after the onset of infarction was significantly different from that in group 1 (25.0% vs 71.4%, p less than 0.03). The data suggest that reperfusion with counterpulsation is more effective when carried out early. Patients who develop shock more than 18 hours after the onset of symptoms of infarction appear to benefit most if treated with counterpulsation alone.

Adult↗

PubMed1995

Benefits of aortic and pulmonary counterpulsation using dynamic latissimus dorsi myoplasty.

BACKGROUND: Intraaortic and pulmonary artery counterpulsation are useful techniques to support circulation during either left or right ventricular dysfunction. Electrically stimulated skeletal muscles wrapped around the aorta, used as means of cardiac failure treatment, have proved to be an effective method of handling experimental left ventricular failure. In this article we report an induced cardiac failure model in acute open chest dogs and describe the hemodynamic improvement of simultaneous aortic and pulmonary artery counterpulsation. METHODS: This was achieved with a bilateral latissimus dorsi muscle flap, stimulated with a software written in C++ for Windows. Dynamic aortomyoplasty was performed using the left latissimus dorsi muscle flap around the descending aorta, and dynamic pulmonaromyoplasty was achieved wrapping the pulmonary trunk with the right latissimus dorsi muscle flap. In all animals blood pressures and cardiac output were measured after cardiac failure induced by a high-dose of propranolol hydrochloride (3 mg/kg intravenously) before and after latissimus dorsi muscle flap stimulation. RESULTS: Aortopulmonary counterpulsation resulted in a significant increase in mean aortic pressure, mean pulmonary pressure, and cardiac output. In addition, a significant decrease was observed in end-diastolic left ventricular pressure, systemic vascular resistance, and pulmonary vascular resistance. Subendocardial viability index (diastolic pressure-time index/systolic tension-time index) in aortomyoplasty and tension time index in pulmonaromyoplasty showed significant improvement when cardiac assistance was performed by electrical stimulation of both muscles (p = 0.037 and p = 0.001, respectively). CONCLUSIONS: Treatment of experimentally induced cardiac failure using aortopulmonary counterpulsation allows effective hemodynamic improvement in open-chest dogs.

Animals↗

PubMed2003

External counterpulsation therapy improves endothelial function in patients with refractory angina pectoris.

OBJECTIVES: The goal of this study was to investigate the influence of short-term external counterpulsation (ECP) therapy on flow-mediated dilation (FMD) in patients with coronary artery disease (CAD). BACKGROUND: In patients with CAD, the vascular endothelium is usually impaired and modification or reversal of endothelial dysfunction may significantly enhance treatment. Although ECP therapy reduces angina and improves exercise tolerance in patients with CAD, its short-term effects on FMD in patients with refractory angina pectoris have not yet been described. METHODS: We prospectively assessed endothelial function in 20 consecutive CAD patients (15 males), mean age 68 +/- 11 years, with refractory angina pectoris (Canadian Cardiovascular Society [CCS] angina class III to IV), unsuitable for coronary revascularization, before and after ECP, and compared them with 20 age- and gender-matched controls. Endothelium-dependent brachial artery FMD and endothelium-independent nitroglycerin (NTG)-mediated vasodilation were assessed before and after ECP therapy, using high-resolution ultrasound. RESULTS: External counterpulsation therapy resulted in significant improvement in post-intervention FMD (8.2 +/- 2.1%, p = 0.01), compared with controls (3.1 +/- 2.2%, p = 0.78). There was no significant effect of treatment on NTG-induced vasodilation between ECP and controls (10.7 +/- 2.8% vs. 10.2 +/- 2.4%, p = 0.85). External counterpulsation significantly improved anginal symptoms assessed by reduction in mean sublingual daily nitrate consumption, compared with controls (4.2 +/- 2.7 nitrate tablets vs. 0.4 +/- 0.5 nitrate tablets, p <0.001 and 4.5 +/- 2.3 nitrate tablets vs. 4.4 +/- 2.6 nitrate tablets, p = 0.87, respectively) and in mean CCS angina class compared with controls (3.5 +/- 0.5 vs. 1.9 +/- 0.3, p <0.0001 and 3.3 +/- 0.6 vs. 3.5 +/- 0.5, p = 0.89, respectively). CONCLUSIONS: External counterpulsation significantly improved vascular endothelial function in CAD patients with refractory angina pectoris, thereby suggesting that improved anginal symptoms may be the result of such a mechanism.

Aged↗

PubMed2002

Skeletal muscle ventricle aortic counterpulsation: function during chronic heart failure.

BACKGROUND: Skeletal muscle ventricles (SMVs) are pumping chambers formed from latissimus dorsi muscle. The SMV aortic counterpulsator model has been proven to be stable in the long term and provide effective diastolic pressure augmentation in normal dogs. This study seeks to prove that the aortic counterpulsator model can function effectively in chronic heart failure. METHODS: In 6 dogs, pericardium-lined SMVs were created from latissimus dorsi muscle and electrically conditioned for fatigue resistance. Each SMV was attached to the descending thoracic aorta with a two-limb bifurcated graft and the aorta ligated between the limbs. The SMV was stimulated to contract during cardiac diastole at 1:2 to 1:3 ratio. Rapid ventricular pacing was initiated at 220 to 230 beats/min for 7 weeks to induce chronic heart failure. RESULTS: SMV contraction resulted in augmentation of the diastolic pressure time-index by 12.1% (32.8+/-15.4 versus 36.1+/-14.7 mm Hg-s, p < 0.05) at baseline, then by 33.6% (12.9+/-4.4 versus 16.8+/-4.3 mm Hg-s, p < 0.05) after 7 weeks of rapid ventricular pacing. After 7 weeks of rapid ventricular pacing, SMV counterpulsation provided significant afterload reduction with increases in peak left ventricular ejection velocity and stroke volume of 22.7% (142+/-55 versus 168+/-45 mL/s, p < 0.05) and 6.2% (13.0+/-5.1 versus 13.7+/-5.2 mL, p < 0.05), respectively. Coronary blood flow was measured in 3 animals at the 7-week measurement; augmentation averaged 47.6% (0.357+/-0.29 versus 0.432+/-0.26 mL/beat, p < 0.05). CONCLUSIONS: The SMV aortic counterpulsator provides improved cardiac assistance relative to the failing heart.

Animals↗

PubMed1997

Intramural blood flow of skeletal muscle ventricles functioning as aortic counterpulsators.

BACKGROUND: Skeletal muscle ventricles (SMVs) working as aortic counterpulsators have provided long-term left ventricular assistance under experimental conditions. However, gradual deterioration of SMV pump function and rupture have been observed, and this may be related to compromised intramural blood flow during synchronized counterpulsation under systemic working conditions. METHODS: Transformed, double-layered SMVs in 6 sheep were stimulated for 3-minute periods (5 V, 30 Hz, burst duration and delay from QRS both 40% of the cardiac cycle) to work as diastolic counterpulsators in the systemic circulation at a 1:2 (SMV:heart) and 1:1 ratio, and on a mock circulation with low-pressure loading conditions at a 1:2 ratio. Thoracodorsal artery blood flow was monitored by ultrasonic flow probe, and intramural blood flow distribution was investigated by fluorescent microspheres. Thoracodorsal venous lactate concentrations were measured before and after each period of stimulation. RESULTS: Thoracodorsal artery blood flow increased significantly (p < 0.001) after stimulation. The magnitude of augmentation (89%; 95% confidence interval, 36% to 163%) was similar for all working conditions studied. Reactive hyperemia was observed after most 1:1 regimens but was rare after 1:2 regimens. A significant (p < 0.05) 15% increase in serum lactate levels was present after 1:1 regimens only. All regimens of stimulation resulted in a significant increase (p < 0.01) in blood flow to sections in the outer wall of the SMV, but a significant increase (p < 0.05) in blood flow to sections in the inner wall was observed only under low loading conditions. CONCLUSIONS: Skeletal muscle ventricles subjected to 1:1 systemic counterpulsation regimens work under partly anaerobic conditions. High loading conditions may compromise SMV inner wall blood flow.

Animals↗

PubMed2003

Enhanced external counterpulsation improves endothelial function in patients with symptomatic coronary artery disease.

OBJECTIVES: The goal of this study was to examine the effect of enhanced external counterpulsation (EECP) on endothelial function. BACKGROUND: Enhanced external counterpulsation improves symptoms and exercise tolerance in patients with symptomatic coronary artery disease (CAD). However, the exact mechanisms by which this technique exerts its clinical benefit are unclear. METHODS: Reactive hyperemia-peripheral arterial tonometry (RH-PAT), a noninvasive method to assess peripheral endothelial function by measuring reactive hyperemic response in the finger, was performed in 23 patients with refractory angina undergoing a 35-h course of EECP. In each patient RH-PAT measurements were performed before and after the first, at midcourse, and the last EECP session. In addition, RH-PAT response was assessed one month after completion of EECP therapy; RH-PAT index, a measure of reactive hyperemia, was calculated as the ratio of the digital pulse volume during reactive hyperemia divided by that at rest. RESULTS: Enhanced external counterpulsation led to symptomatic improvement (>/=1 Canadian Cardiovascular Society class) in 17 (74%) patients; EECP was associated with a significant immediate increase in average RH-PAT index after each treatment (p < 0.05). In addition, average RH-PAT index at one-month follow-up was significantly higher than that before EECP therapy (p < 0.05). When patients were divided by their clinical response, RH-PAT index at one-month follow-up increased only in those patients who experienced clinical benefit. CONCLUSIONS: Enhanced external counterpulsation enhances peripheral endothelial function with beneficial effects persisting at one-month follow-up in patients with a positive clinical response. This suggests that improvement in endothelial function may contribute to the clinical benefit of EECP in patients with symptomatic CAD.

Aged↗

PubMed2003

Contemporary utilization and outcomes of intra-aortic balloon counterpulsation in acute myocardial infarction: the benchmark registry.

OBJECTIVES: We sought to examine contemporary utilization patterns and clinical outcomes in patients with acute myocardial infarction (AMI) requiring intra-aortic balloon pump (IABP) counterpulsation. BACKGROUND: Despite increasing experience with and broadened indications for intra-aortic counterpulsation, the current indications, associated complications, and clinical outcomes of IABP use in AMI are unknown. METHODS: Between June 1996 and August 2001, data were prospectively collected from 22,663 consecutive patients treated with aortic counterpulsation at 250 medical centers worldwide; 5,495 of these patients had AMI. RESULTS: Placement of an IABP in AMI patients was most frequently indicated for cardiogenic shock (27.3%), hemodynamic support during catheterization and/or angioplasty (27.2%) or prior to high-risk surgery (11.2%), mechanical complications of AMI (11.7%), and refractory post-myocardial infarction unstable angina (10.0%). Balloon insertions were successful in 97.7% of patients. Diagnostic catheterization was performed in 96% of patients, and 83% underwent coronary revascularization before hospital discharge. The in-hospital mortality rate was 20.0% (38.7% in patients with shock) and varied markedly by indication and use of revascularization procedures. Major IABP complications occurred in only 2.7% of patients, despite median use for three days, and early IABP discontinuation was required in only 2.1% of patients. CONCLUSIONS: With contemporary advances in device technology, insertion technique, and operator experience, IABP counterpulsation may be successfully employed for a wide variety of conditions in the AMI setting, providing significant hemodynamic support with rare major complications in a high-risk patient population.

Adult↗

PubMed1999

The multicenter study of enhanced external counterpulsation (MUST-EECP): effect of EECP on exercise-induced myocardial ischemia and anginal episodes.

OBJECTIVES: The purpose of this study was to assess safety and efficacy of enhanced external counterpulsation (EECP). BACKGROUND: Case series have shown that EECP can improve exercise tolerance, symptoms and myocardial perfusion in stable angina pectoris. METHODS: A multicenter, prospective, randomized, blinded, controlled trial was conducted in seven university hospitals in 139 outpatients with angina, documented coronary artery disease (CAD) and positive exercise treadmill test. Patients were given 35 h of active counterpulsation (active CP) or inactive counterpulsation (inactive CP) over a four- to seven-week period. Outcome measures were exercise duration and time to > or =1-mm ST-segment depression, average daily anginal attack count and nitroglycerin usage. RESULTS: Exercise duration increased in both groups, but the between-group difference was not significant (p > 0.3). Time to > or =1-mm ST-segment depression increased significantly from baseline in active CP compared with inactive CP (p = 0.01). More active-CP patients saw a decrease and fewer experienced an increase in angina episodes as compared with inactive-CP patients (p < 0.05). Nitroglycerin usage decreased in active CP but did not change in the inactive-CP group. The between-group difference was not significant (p > 0.7). CONCLUSIONS: Enhanced external counterpulsation reduces angina and extends time to exercise-induced ischemia in patients with symptomatic CAD. Treatment was relatively well tolerated and free of limiting side effects in most patients.

Adult↗